1. Field of the Invention
This invention relates to preparation of an effluent gas stream containing maleic anhydride as a result of oxidizing an organic material having at least 4 carbon atoms, and known to be a precursor for maleic anhydride in the presence of a catalyst functioning as a partial exidation catalyst at conditions favoring formation and preservation of maleic anhydride.
2. PRIOR ART
The preparation of maleic anhydride from normal butene is described in a series of Ueeda U.S. Pat. Nos. 3,906,008, 3,975,407, and 4,003,920 all the disclosures of which are deemed here reiterated. M. Ai has described "The Activity of WO.sub.3 Based Mixed Oxide Catalysts", in the Journal of Catalysis, Volume 49, pages 305-312, and Volume 49, pages 313-319 (1977). A significant variety of methods for making maleic anhydride have been operated commercially for at least a while during recent decades. Benzene has continued to be a preferred feed stock but the oxidation of butene over a vanadium phosphate type of catalyst has been chosen for some recent plants.
Notwithstanding the persistent efforts by many researchers the search for an appropriate catalyst for manufacturing maleic anhydride has not ended.